The focus of this book is on the past and present standards of rationality of religion, which have functioned as significant regulators of thoughts and practical actions of various social groups. Determining these standards of rationality requires several general assumptions. One, for example, is that religion is of this world and serves the needs of this world. Another assumption is represented in philosopher Gottfried Wilhelm von Leibniz's principle that nothing is without reason (nihil est sine ratione). (Series: Development in Humanities - Vol. 2)